The proposed work will result in a characterized prototype instrument that will facilitate the identification of a broad range of analytes in small volumes of human blood, urine, saliva and other readily obtainable biological fluids with little sample preparation. The proposed instrument will incorporate two related analytical approaches, grating-coupled surface Plasmon resonance analysis and surface plasmon-enhanced fluorescence to provide a broad dynamic range coupled with highly sensitive measurements. Analyte selectivity is achieved through the use of capture ligands e.g. antibodies, aptamers, etc. Sample volumes required for the proposed prototype are on the order of 0.3 to 0.5 ml. The proposed instrument will be designed to perform multiple (approx.1000) analyses simultaneously. Gold-clad superparamagnetic nanobeads will be used to increase the selectivity of measurements by transporting analyte to capture sites in a controlled magnetic field. The instrument will be characterized through the use of two commonly encountered toxicants and a bacterial toxin. Software-controlled automation will make the instrument easy to use and suitable for use out of the laboratory. The instrument will provide an inexpensive and efficient way to directly identify or monitor suspected toxicants. PUBLIC HEALTH RELEVANCE: There is a critical need for highly sensitive and specific techniques capable of defining the exposure levels of human and animal populations to the broad range of toxins and toxicants found in the environment. We propose to develop an instrument that will meet this need without many of the limitations that constrain existing technologies. The proposed approach will perform large number (up to a thousand) simultaneous analyses in less than hour. The analyses will identify and quantitate the presence or absence of hundreds of potential toxicants that a patient might encounter without foreknowledge of the contaminant's identity. The technology upon which the proposed instrumentation is based is suitable for use in a clinical laboratory and, with further development extendable to a point-of-care instrument. The instrument will require small sample volumes of biological fluids such as blood, urine or saliva.